In 2012, the US Navy test-fired a rail
gun for the first time and later announced plans to put one on
the guided-missile destroyer USS Zumwalt.

In 2014, the Navy mounted and tested
a laser on the USS Ponce, an amphibious transport dock,
successfully taking out the engine of a small inflatable boat
containing a rocket-propelled grenade.

More recently, the US Army successfully tested
a laser mounted on an Apache helicopter, and the Air Force is
planning to put
lasers on AC-130s.

Despite these many successful tests, the two weapons aren't
currently operational, Bob Freeman, a spokesman for the Office of Naval Research, told
Business Insider, notwithstanding CNN's recent story
claiming that the laser aboard the Ponce is "ready to be
fired at targets today and every day by Capt. Christopher Wells
and his crew."

The laser aboard the Ponce is "not the final product,"
Freeman said. It is a low-energy laser that has been tested to
shoot down drones. If the Ponce is threatened, they'll still use
conventional weapons.

So questions remain about when the weapons will be
operational, how they will be used, and which will be used
more.

One
of two electromagnetic-railgun prototypes on display aboard joint
high speed vessel USS Millinocket at Naval Base San Diego, July
8, 2014.US
Navy photo

"They both have unique capabilities," but, Freeman said,
"it seems to me you have less options with rail guns."

Lasers have more capabilities in that they can be set to
different energy levels, giving the operators the option to deter
or take out targets.

For example, if a US ship perceives an aircraft as a
threat, "you can put [the laser] on low-power and scintillate the
cockpit" and make the pilot turn around, Freeman said. He wasn't
exactly sure what the enemy pilot would experience but said he or
she would see the laser and probably wouldn't be injured.

Or, if needed, the operators could turn the energy levels
up and destroy the enemy target, either by melting precision
holes through the craft or "cutting across" it, he said.

High-energy lasers, he added, are "still in
development."

But for larger targets, such as enemy ships, rail guns
would probably be the best weapon.

"It packs a punch ... and can go through steel walls,"
Freeman said.

Once they are both operational, the US military will use
them along with conventional weapons, and it'll take years of
evolution for one to make the other, or even conventional
weapons, obsolete, Freeman said.

"They both have challenges to go through," he told Business
Insider, including where to get the power needed to fuel them.
But they also offer other benefits in addition to their
lethality: They're cheaper and can even be safer for sailors, as
they don't require stores of ammunition that can explode.

As for exact tactics regarding how and when to use rail
guns and lasers, the Navy and other branches employing them will
decide once they're operational, Freeman said.